Hi
I try to simulate a simple TFM-DEM hybrid model, But the TFM particles do not exist.
I have defined 3 types of particles, DEM by particle_input.dat and TFM particles by the initial condition. But I can’t see the TFM bed in VTK.
This problem even exists in the MFIX software legacy tests.
My simulation files are here: HH.zip (4.3 KB)
Thanks
The TFM (Two Fluid Model) is not a Lagrangian technique. There are no discrete particles!
You visualize the bed with ep_g (void fraction).
BTW, the hybrid model is not officially supported by the GUI and you may encounter issues.
Seems like there may be an issue. I opened your project and can confirm that there is no TFM bed. If I delete the DEM solid, then I get the TFM bed.
Thanks for your response.
As you said, I use EP_G but nothing is visible. Do you have a simple Hybrid project in which the TFM bed can be seen correctly?
Because this problem can be seen even in the hybrid legacy tests presented in MFIX 19.3.1 source tarball.
I think this problem is due to the inactivity of particle generation in the DEM tab because in hybrid projects we have to use particle_input for DEM particles. When this option is disabled, the software uses the particle_input file and it no longer uses the initial conditions.
It doesn’t look like the TFM IC is getting set correctly, hence EP_G being set to 1 in the “bed” region.
There are various articles that have used this method, and I also read several topics in the forum that did not encounter this problem(such as this topic Errors of Hybrid model with Cut-Cell ). Could this be a bug in the software version? Or am I doing something wrong in the simulation?
The issue was resolved.
To use the hybrid method, it is necessary to use the Garg 2012 interpolation method.
Does anyone know why MFIX hybrid only works with GARG 2012 interpolation?
I need to use Mean_Field_Diffusion but it is not possible with GARG 2012.
Hello @arsalanjalali , I am trying to build a hybrid TFM DEM model as well, and a rough sketch of my concept looks like the image ive attached. Can you help me build it or help me with a similiar project file that you’ve worked on, as I am new to MFiX and I am on a very short deadline to understand and build a Hybrid TFM-DEM Model
